network/ifup.sh: save return value of ifup

(cherry picked from commit b4006781e8)

modules.d/40network/ifup.sh

@@ -373,6 +373,7 @@ for p in $(getargs ip=); do
                 do_static ;;
         esac
     done
+    ret=$?
 
     > /tmp/net.${netif}.up
 
@@ -380,7 +381,7 @@ for p in $(getargs ip=); do
         dhcp|on|any|dhcp6)
             ;;
         *)
-            if [ $? -eq 0 ]; then
+            if [ $ret -eq 0 ]; then
                 setup_net $netif
                 source_hook initqueue/online $netif
                 if [ -z "$manualup" ]; then